This article refers to the Contract overview. For the Contract finale, see The E.C.U Job/Finale.

“Jump a freight train and steal the prototype standalone engine control units inside.”
— Contract description
The E.C.U Job is a Contract introduced to Grand Theft Auto Online in the Los Santos Tuners update.
Description
The Contract can be selected if it is one of the three available contracts on the GTA Online Protagonist's Job Board in their Auto Shop.
Sessanta will tell the player that KDJ wants an ECU from an armored train so he can give it better uses. The player will need to learn which one of the container on the train will be holding the ECUs, and learn when they are due to be transported to be able to find a way to stop the train in order to rob it.
The Contract, like other Contracts, consists of two Free Mode preparation missions and one finale.
Preparations
Train Inventory
Main article: Planning Work: Train Inventory
“Identify which of the train's containers will be holding the ECUs.”
— Preparation description.
Schedule
Main article: Planning Work: Schedule
“Learn when the ECUs are due to be transported and find a way to stop the train.”
— Preparation description.
The Robberies
Main article: The E.C.U Job/Finale
“Stop the train, steal the ECUs, and deliver them to the client.”
— Finale description.